GTK+ 2.9.0 has been released. This is the first development release leading up to GTK+ 2.10. For completeness: "GTK+ is a multi-platform toolkit for creating graphical user interfaces. Offering a complete set of widgets, GTK+ is suitable for projects ranging from small one-off tools to complete application suites."

Which would mean either GPL everything or anyone wanting to work on Mozilla would need to buy a commercial Qt license (and they're not cheap).

No. Read above.

Qt wasn't open source at all at the time the Netscape source code was first released, so the whole point is moot.

Which matters how? Motif got used for quite some time as I remember, a GTK port happened but even today it's not that great (which is why many people say Epiphany should be Gnome's browser). The Windows port is many, many times better.

Qt was open sourced, but it just didn't meet some peoples' definition.

I find all this totally pointless though because KDE already has a browser in Konqueror, a great engine in KHTML and it will be a great fully fledged web browser in KDE 4.